The Douma chemical weapons investigation and the role of Ian Henderson

Brian Whitaker
9 min readJan 2, 2020

Many of the recent claims about “irregularities” in the OPCW’s investigation of a suspected chemical attack in Syria revolve around an employee called Ian Henderson. His exact role has been a matter of dispute but now leaked documents give a clearer picture.

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In a report last March the OPCW’s Fact-Finding Mission (FFM) found “reasonable grounds” for believing a toxic chemical had been used as a weapon in the Syrian city of Douma.

That conclusion was immediately disputed by the Assad regime along with its chief ally, Russia, and various elements on social media. Criticism of the investigation has now turned into a campaign to discredit the OPCW more generally.

One of the main allegations is that the outcome of the Douma investigation was “pre-ordained” by western powers and that OPCW staff who disagreed were systematically ignored, sidelined and over-ruled.

Documents posted online by WikiLeaks — the latest batch appeared on Friday — are said to support these claims, though on the whole they don’t. They give plenty of examples where suggestions or criticisms from staff, far from being dismissed, were actually taken on board.

However, the documents do identify one staff member who clearly had serious issues with his employer. Ian Henderson, a South African, had long-standing connections with the OPCW — he was one of the first inspection team leaders recruited after its formation in 1997 — but in May this year he was suspended from duty and escorted out of the office.

Henderson in Douma

Henderson’s supporters say he was a member of the FFM who has later excluded because of his dissenting views. The OPCW says he was not officially a member of the FFM and, judging by the leaked documents, his bosses regarded him as a loose cannon, meddling where he was not wanted.

There’s no evidence in the leaked documents that he was ever formally recognised as a member of the FFM though he did become quite heavily involved in its activities during the deployment to Douma.

When the FFM arrived in Syria to investigate the alleged chemical attack, Henderson was already in Damascus as a liaison officer in the OPCW’s Command Post there and he continued in that role for five more weeks after the FFM had left.

During the FFM’s deployment Henderson spent several days with them on the ground, and according to the OPCW there was nothing unusual about that: it was “customary” to “temporarily” assist.

He is said to have made inspection visits to an alleged chemical weapons production facility, to “Location 4” where one of two gas cylinders had been found, and to a hospital nearby. He later went to an undisclosed location to re-examine the cylinders and apply seals to them.

Continuing involvement

Henderson continued “temporarily” assisting the FFM after its return from Syria. For example, he says he wrote “two narratives” for the initial draft of its Interim Report issued in July 2018. Based on his known activities in Douma, it’s likely these were Annex 7 (about Location 4) and Annex 8 (about the alleged production facility).

A few days before the Interim Report was published he also became involved in an argument about the wording of a paragraph which said chlorinated organic chemicals (COCs) had been detected in environmental samples from Douma. The COCs were only at trace levels and the question was whether or not to mention this. Either way, there was a risk that people would misinterpret it. Henderson was reportedly one of four staff who initially persuaded Sami Barrek, the FFM’s Tunisian team leader, to mention trace levels in the report — though Barrek rescinded that decision a day before publication.

Investigating the cylinders

Henderson, in his own opinion, was “clearly the most qualified team member” to investigate the two cylinders. He wrote in a memo that he had been “assigned the task of analysis and assessment” of the cylinders’ ballistics — though the memo didn’t say who assigned him. In one of his emails he put it more modestly, saying he had been “tasked to contribute to the review of ‘location and munition’.”

In the meantime, however, the FFM had decided to seek outside help in assessing the cylinders and publicly announced that it would be consulting “suitable experts”.

As a result of that decision it might be expected that someone would have told Henderson to stop his own work on the cylinders but it seems no one did — at least, not explicitly. Managers apparently tried to discourage him from continuing but he resisted. “In subsequent weeks I found that I was being excluded from the work, for reasons not made clear,” he wrote. “I was also assigned to other missions. However I made clear that I would complete the work and submit my report to the FFM.”

‘Should not be involved’

Meanwhile, the cylinders themselves were still in Syria — in government hands because the regime said it wanted them for a “ criminal investigation”. On 30 July 2018 the OPCW’s Contingency Operations Coordination Operational Network (COCOON) held a meeting where the need for further work on the cylinders was discussed. Draft minutes of the meeting were circulated later the same day accompanied by an email inviting comments.

A line in the COCOON minutes talked about accessing the cylinders again to take “additional measures and samples for metallurgical analysis” and Henderson responded half an hour later by suggesting this should be changed to “the possibility of retrieving cylinders to HQ, or another deployment to the SAR [Syria] to conduct specific examination and sampling from the cylinders, and the planned conduct of expert studies”.

Henderson’s intervention, and the fact that he had been included among the 18 recipients of the COCOON email, clearly angered team leader Barrek who then fired off a complaint:

“The point regarding FFM and in particular the Douma ongoing work should be discussed with FFM Alpha team. The list of team members was sent recently by [name redacted]. Whom not on that list should not be involved in this matter. Thank you.”

Undeterred by that, Henderson pressed on with his analysis of the cylinders, later describing how he “engaged engineering expertise, to get access to sophisticated engineering computational tools” for his report. There’s no indication in the documents that Barrek or anyone else in the FFM had authorised this work but it’s unlikely Henderson could have completed it without support from somewhere in the organisation. He says it was approved by the OPCW’s Director of Inspectorate, and al-bab understands that the OPCW paid two universities for their technical assistance.

Contradicting the experts

The experts chosen by the FFM were described as internationally recognised, coming from three different countries, working independently and using “different methodologies and approaches for their analyses in order to produce more comprehensive results”. The positioning of the Douma cylinders, as seen by the FFM and in photos and videos posted online, suggested they had caused holes by hitting concrete roofs, with one of them ending up on a bed in the room below. Using computer modelling and other techniques, the experts concluded that the damage at the scene could indeed have been caused by the cylinders crashing into the roofs.

The experts submitted their findings to the FFM in December 2018 but Henderson was still waiting for his own results and didn’t receive them until late the following January. He then drafted a 15-page executive summary and circulated it for comments.

At that point other staff became aware that Henderson’s conclusions contradicted those of the FFM’s experts. His report argued that the cylinders were more likely to have been “manually placed” in the spot where they were found than dropped from the air. If true, this could be viewed as reinforcing claims that rebels had faked the alleged chemical attack.

Delivery problems

After circulating his draft Henderson made some revisions and in mid-February began trying to hand it over to FFM team leaders. But his problem — as leaked emails show — was that none of them seemed eager to receive it.

By now, Henderson was becoming anxious. If he couldn’t submit his document soon it would be too late, because publication of the FFM’s Final Report on Douma was imminent. He was also concerned at not having been offered a chance to see the Final Report in draft form. He complained:

“There are some members of the on-site team at the incident location, including myself, who have been wondering if we will be requested (or given the opportunity) to review the draft report before it comes out.”

Henderson wasn’t the only one wanting to know what the report would say. Governments were interested too and the OPCW was anxious to prevent any leaks ahead of publication. For that reason, access to the draft was restricted to a very small group. As a result of various incidents, including cyber attacks and the discovery of four Russian intelligence agents attempting to hack into its wifi system from a car park next to its headquarters, the organisation had also been tightening up generally on information security.

‘Dropping it off’

Eventually, on the thorny question of who would receive Henderson’s document, a decision was made that he should hand it to Sebastien Braha, Chief of Cabinet in the Director-General’s office. But by the time this news reached Henderson, on 28 February, he had already done something else with the document.

As he was not going to be available for the next couple of days, he had “dropped it off” ( his own words) at Documents Registration and Archiving (DRA) and sent an email saying it could be collected from there. This was an irregular use of the secure depository since it wasn’t intended for unofficial reports.

On hearing what had happened, Chief of Cabinet Braha issued an ominous-sounding email saying he wanted to see Henderson “to discuss the situation, not the document. Subsequently, we will see how to deal with the document itself.”

He added:

“Please get this document out of DRA, as DRA is instructed to specifically NOT deal with any non-routine missions, until further instruction. And please remove all traces, if any, of its delivery/storage/whatever in DRA.”

Later that afternoon Braha sent a second email:

“I have a further question that I will need to see answered, in a subsequent meeting: under whose authority was this work conducted, outside FFM authority and dedicated highly secured network, by someone who was not part of the FFM?”

The following day — 1 March — the FFM’s Final Report was published, minus any mention of Henderson’s findings.

But Braha’s order to “remove all traces” of Henderson’s document from the DRA didn’t mean all copies were to be destroyed. Nor did publication of the FFM’s report mean the OPCW’s investigation of Douma was at an end.

A question of blame

A problem with Henderson’s findings was that — in the words of Director-General Arias — his talk of manually-placed cylinders “pointed at possible attribution” of responsibility and thus fell outside the FFM’s mandate. The official role of the FFM was to establish facts about suspected chemical attacks but not to attribute blame.

This wasn’t an insuperable problem, however, because a new OPCW body had recently been set up with the specific purpose of attributing blame. This was the Investigation and Identification Team (IIT) which had been established the previous June at a special session of the OPCW’s governing body, the Conference of the States Parties, in the face of opposition from Syria and Russia. Its brief was to identify “those who were the perpetrators, organisers, sponsors or otherwise involved” in cases where the FFM had already established that a chemical weapon was likely to have been used — which would include Douma.

At the time of the FFM’s Final Report on Douma, the IIT was not yet fully operational (and so far it hasn’t published any findings) but it offered a possible way forward on the question of what to do about Henderson’s document.

Henderson meets the IIT

On 12 March Henderson was called to a meeting with the IIT. Writing two days later in a memo to Director-General Arias, he said he had been asked to “contribute to their initial briefings” on the Douma case: “I was advised by the head of IIT that they expected I would provide everything I knew of the case, and this I subsequently did.”

Henderson ended his memo on a conciliatory note saying his only interest was in “sound technical rigour” and his document had been intended as a basis for discussion:

“I must stress that I hold no opinion, interest or strong views on the technical part of the matter, nor any interest in the political outcomes. My interest is in sound technical rigour; the science, engineering and facts will speak for themselves.

“Obviously my current assessment is that the FFM report is incomplete, for reasons that will become clear once my report is properly assessed by experts. At the very least, this was intended to be the basis for deliberation within the team, involving the external experts as necessary, to reach consensus or to agree to disagree. If I am wrong I will humbly apologise for the disruption this may have caused.”

What happened with Henderson during the next few weeks is still unknown but on 13 May a leaked copy of his document surfaced on the internet. Shortly after that, Henderson was suspended and escorted out the OPCW headquarters in what was described as “a less than dignified manner”.

Further reading:
Syria and chemical weapons
A compilation of blog posts and documents looking at the arguments and the evidence

Originally published at



Brian Whitaker

Former Middle East editor of the Guardian. Website: Author of 'Arabs Without God'.